U.S. patent application number 16/483037 was filed with the patent office on 2020-04-16 for measuring arrangement having an optical transmitter and an optical receiver.
The applicant listed for this patent is OSRAM Opto Semiconductors GmbH. Invention is credited to Dirk Becker, Martin Haushalter, Claus Jaeger.
Application Number | 20200116829 16/483037 |
Document ID | / |
Family ID | 61148216 |
Filed Date | 2020-04-16 |
United States Patent
Application |
20200116829 |
Kind Code |
A1 |
Becker; Dirk ; et
al. |
April 16, 2020 |
Measuring Arrangement Having an Optical Transmitter and an Optical
Receiver
Abstract
A measuring arrangement having an optical transmitter and an
optical receiver are disclosed. In an embodiment a measuring
arrangement includes an optical transmitter configured to transmit
electromagnetic measuring radiation into a transmission space, an
optical receiver configured to receive measuring radiation
reflected by an object in a reception space and a covering
configured to reduce reception of an interference radiation by the
receiver, wherein the interference radiation is measuring radiation
not reflected by the object.
Inventors: |
Becker; Dirk; (Langquaid,
DE) ; Haushalter; Martin; (Regensburg, DE) ;
Jaeger; Claus; (Regensburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OSRAM Opto Semiconductors GmbH |
Regensburg |
|
DE |
|
|
Family ID: |
61148216 |
Appl. No.: |
16/483037 |
Filed: |
January 30, 2018 |
PCT Filed: |
January 30, 2018 |
PCT NO: |
PCT/EP2018/052209 |
371 Date: |
August 1, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01S 17/04 20200101;
G01V 8/14 20130101; G01S 7/4814 20130101; G01S 7/4813 20130101;
G01S 7/4816 20130101 |
International
Class: |
G01S 7/481 20060101
G01S007/481; G01V 8/14 20060101 G01V008/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 1, 2017 |
DE |
102017101945.6 |
Claims
1-20. (canceled)
21. A measuring arrangement comprising: an optical transmitter
configured to transmit electromagnetic measuring radiation into a
transmission space; an optical receiver configured to receive
measuring radiation reflected by an object in a reception space;
and a covering configured to reduce reception of an interference
radiation by the receiver, wherein the interference radiation is
measuring radiation not reflected by the object.
22. The arrangement according to claim 21, wherein the covering is
at least partly arranged in the transmission and reception spaces,
wherein the covering comprises a passage area, wherein the passage
area is transparent for the measuring radiation and transparent for
reflected measuring radiation, wherein the passage area at least
partially limits the transmission and reception spaces, and wherein
the passage area is embodied as a continuous surface.
23. The arrangement according to claim 21, wherein the transmitter
is arranged in the reception space, wherein the reception space
abuts on the receiver at a reception surface, wherein the
transmitter covers a partial surface of the reception surface
against reception of reflected measuring radiation, wherein the
reception surface comprises an inactive surface area, wherein the
inactive surface area at least partly comprises a ring shape around
a shadowed partial surface, and wherein the receiver does not
evaluate measuring radiation striking in the inactive surface
area.
24. The arrangement according to claim 23, wherein no reception
surface is provided in the inactive surface area or the reception
surface is covered or the reception surface is deactivated.
25. The arrangement according to claim 24, wherein a lens is held
in a retainer at a distance to the transmitter, wherein the
retainer is arranged on the reception surface or the receiver, and
wherein the retainer surrounds or covers the transmitter.
26. The arrangement according to claim 23, further comprising a
lens located in the transmission space, wherein the lens is
configured to focus the radiation on a target region.
27. The arrangement according to claim 26, wherein the lens is
formed from a molding material, and wherein the lens covers the
transmitter and at least partially the receiver.
28. The arrangement according to claim 21, wherein the receiver
comprises a reception surface configured to receive the reflected
measuring radiation, wherein the reception surface is divided up
into at least two partial surfaces, wherein at least a partial
surface of the partial surfaces is configured to be activated or
deactivated, wherein the receiver is configured to detect the
reflected measuring radiation via the partial surface in an active
state, and wherein the receiver is configured to not detect the
reflected measuring radiation via the deactivated partial surface
in an inactive state.
29. The arrangement according to claim 28, further comprising a
covering at least partly arranged in the transmission and reception
spaces, the covering comprising a passage area, the passage area
configured to be transparent for the measuring radiation and for
reflected measuring radiation, wherein the passage area at least
partly comprises the transmission space and at least partly the
reception space, and wherein the passage area comprises a
continuous surface.
30. The arrangement of claim 28, wherein the partial surfaces have
a strip-like configuration, and wherein the transmitter is arranged
laterally to the receiver.
31. The arrangement of claim 28, wherein the partial surfaces have
a ring-shaped configuration, wherein the transmitter is arranged in
the reception space, wherein the transmitter covers a part of the
reception space against reception of reflected measuring radiation,
and wherein the reception space abuts on the receiver in the
reception surface.
32. The arrangement of claim 31, wherein the partial surfaces have
a ring-shaped configuration, or wherein the partial surfaces are
striped rings with angled corner areas.
33. The arrangement of claim 28, wherein the reception surface is
configured as a segmented photodiode, wherein the partial surfaces
represent segments of the photodiode, and wherein the segments are
evaluated independently.
34. The arrangement according to claim 21, wherein the receiver
comprises a reception surface configured to receive the reflected
measuring radiation, wherein the entire reception surface is
located in the reception space, and wherein the reflected measuring
radiation strikes the receiver via a passage area.
35. The arrangement according to claim 21, wherein the receiver
comprises a reception surface configured to receive the reflected
measuring radiation, and wherein the reception surface has at least
a partial circle shape corresponding to the reception space.
36. The arrangement according to claim 21, wherein the transmitter
and/or the receiver comprises an optical element configured to
guide the radiation.
37. The arrangement according to claim 21, wherein the transmitter
is arranged between two legs of a U-shaped reception surface.
38. The arrangement according to claim 21, wherein the transmitter
is arranged on the receiver.
39. The arrangement according to claim 21, wherein the receiver
comprises a reception surface arranged on an evaluation chip, and
wherein the reception surface has a smaller area than the
evaluation chip.
Description
[0001] This patent application is a national phase filing under
section 371 of PCT/EP2018/052209, filed Jan. 30, 2018, which claims
the priority of German patent application 102017101945.6, filed
Feb. 1, 2017, each of which is incorporated herein by reference in
its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a measuring arrangement
having an optical transmitter and an optical receiver.
BACKGROUND
[0003] In the state of the art, an optical transmitter and an
optical receiver are provided side by side on a carrier. In order
to reduce interference radiation which is a measuring radiation not
reflected by the object, a housing cap is provided between the
object and the transmitter and receiver arrangement, the housing
cap having two apertures. One aperture is arranged above the
transmitter and a second aperture above the receiver. Reception of
interference radiation may in particular be reduced by means of the
aperture above the receiver.
SUMMARY OF THE INVENTION
[0004] Embodiments provide an improved measuring arrangement
comprising an optical transmitter and an optical receiver.
[0005] An advantage of the proposed measuring arrangement may
consist in providing a further reduction of interference radiation.
For this purpose, means are provided that reduce reception of
interference radiation that represents measuring radiation not
reflected by the object.
[0006] In a first embodiment, a covering is provided for this
purpose, the covering being at least partially arranged in the
transmission space and in the reception space between transmitter
and receiver and the object to be measured. The covering comprises
a passage area that is transparent for the measuring radiation and
for the measuring radiation reflected by the object. The passage
area comprises the transmission space and the reception space. In
addition, the passage area is configured as a continuous surface.
The transmitter and the receiver are arranged very closely to each
other so that one single passage area may be used. By means of
this, a simplified design is achieved which additionally allows for
a reduction in the reception of interference radiation.
[0007] In a second embodiment, the transmitter is arranged in the
reception space, the transmitter covering a part of the reception
space against a reception of reflected measuring radiation. In
order to reduce interference radiation, the reception surface of
the receiver comprises an inactive surface area. In the inactive
surface area, the received reflected measuring radiation is not
evaluated. The inactive surface area comprises at least a ring
shape arranged around the partial surface shadowed by the
transmitter on the reception surface. The ring shape may be
embodied as a continuous surface having a ring shape in the outer
area. The surface may comprise the reception surface shadowed by
the transmitter.
[0008] By arranging the transmitter above the receiver in the
reception space, construction space is saved. As a result, the
arrangement can be provided requiring only little space.
Furthermore, an increase of interference radiation due to arranging
the transmitter in the reception space may be compensated for or at
least reduced by providing the inactive surface area. The inactive
surface area is embodied in such a way that at least a part of the
interference radiation caused by the arrangement of the transmitter
in the reception space is not determined and evaluated by the
receiver. The inactive surface area may be realized by not
providing a reception surface in the inactive surface area or by
covering the provided reception surface or and by protecting it
against reception of reflected measuring radiation. Moreover, the
inactive surface area may be realized by the fact that a provided
reception surface is not active and not used for reception of
reflected measuring radiation.
[0009] In a third embodiment, a reception surface of the receiver
provided for reception of a reflected measuring radiation is
divided up into at least two partial surfaces. In this context, at
least one partial surface may be configured in such a way that it
may be activated and/or deactivated. In an activated state, the
partial surface is configured to detect the reflected measuring
radiation. In a deactivated state, the partial surface is
configured to not detect the reflected measuring radiation. In this
way, the receiver with the two partial surfaces may be put to
individual use.
[0010] Depending on the chosen embodiment, it may be advantageous
to operate both partial surfaces in an active state and to detect
the reflected measuring radiation. In another embodiment, it may be
advantageous to operate the first or second partial surface in the
deactivated state and to not detect any reflected measuring
radiation via the first or, respectively, second partial surface.
This may be particularly advantageous when interference radiation
or a high portion of interference radiation is detected via one of
the two partial surfaces. In this manner, the receiver may be
individually set to a predetermined measuring situation. For
example, the measuring situation may be influenced by the type of
object or by the distance of the object with regard to the
measuring arrangement.
[0011] It may furthermore be advantageous to operate the first as
well as the second partial surface in the deactivated state,
particularly if a high portion of interference radiation is
received on both partial surfaces and as a result, the reflected
measuring radiation at issue may no longer be detected to a
sufficient extent.
[0012] In a variation of the first embodiment, a reception surface
of the receiver is completely located in the reception space that
abuts on the receiver via the passage area. This allows for a
compact design of the reception surface. Moreover, the existing
reception surface is used efficiently because the entire reception
surface is located in the reception space that is determined by the
passage area.
[0013] In a further first embodiment, the reception surface is at
least partially configured as a circle. Due to the partial circle
shape, a precise limitation of the reception surface may be
realized on a reception space that has a partial circle shape in
cross section. In this context, the passage area is embodied in
such a way that the reception space on the reception surface of the
receiver has at least a partial circle shape. For this, the passage
area has at least a partial circle shape. In a simple embodiment,
the passage area may have a circle shape. For example, the
reception surface may have a half-circle shape. By means of this, a
compact design requiring limited space may be realized.
[0014] In a further first embodiment, the transmitter and/or the
receiver comprise an optical element, in particular a lens for an
improved guiding of radiation. By means of at least one optical
element having an improved guiding of radiation, an improved
guiding of the transmitted measuring radiation and/or of the
reflected and received measuring radiation may be achieved.
Thereby, the transmitter as well as the reception surface of the
receiver may be realized in a smaller area with the same measuring
performance. In addition, the design of the measuring arrangement
may be realized requiring limited space and with smaller
design.
[0015] The optical element may be realized as an individual lens
for the transmitter and/or the receiver. In addition, an optical
element may be provided for the transmitter as well as for the
receiver. In this context, the optical element extends over the
transmission space of the transmitter as well as over the reception
space of the receiver. Depending on the chosen embodiment, the
optical element, particularly the lens or the lenses, may be
embodied as a molded optical element produced from a molding
material. Depending on the chosen embodiment, a transfer-molded
element may be used as an optical element having low optical
guiding capacity but providing protection of the transmitter and/or
the receiver.
[0016] In a further first embodiment, the reception surface of the
receiver has a U-shape with two legs and a connecting region. In
this arrangement, it is advantageous for a low space requirement if
the transmitter is at least partially or fully arranged in a region
between the two legs. In addition, in this embodiment it may be
advantageous to configure an outer contour of the reception surface
abutting on an edge area of the reception space as a circle shape
or in the shape of the limiting surface of the reception space.
Thereby, the available surface is efficiently used for the
transmitter and the reception space.
[0017] Depending on the chosen embodiment, the reception surface
may be formed of a plurality of separate partial reception
surfaces. The partial reception surfaces, too, may have a U-shape
and at least partly receive the transmitter between the two legs of
the U-shape. The partial reception surfaces may be square or,
respectively, rectangular and they may in part protrude laterally
over the reception space. It is true that thereby a part of the
reception surface is provided without receiving functionality,
however, the design of the reception surface is simple and
inexpensive.
[0018] In a further second embodiment, no reception surface is
provided in the inactive surface area of the reception surface. As
a result, the actual reception surface is limited to a surface area
that is actually provided for receiving a measuring radiation.
[0019] In a further second embodiment, the reception surface is
provided in the inactive surface area, however, it is covered and
protected against reception of radiation. In this manner, the
inactive surface area of the reception surface is protected against
reception of interference radiation, but also against reception of
a measuring radiation. The covered area of the reception surface is
particularly configured with so large a size or, respectively, in a
way that low or no interference radiation is received.
[0020] In a further second embodiment, the reception surface is
provided in the inactive surface area, however, it is deactivated.
This may, e.g., be realized by a segmented reception surface,
wherein a segment of the reception surface forms the inactive
surface area and said segment is deactivated and not used for
receiving any measuring radiation.
[0021] In a further second embodiment, a lens is provided in the
transmission space of the transmitter in order to focus the
radiation on a desired target area. By means of this, an improved
measuring evaluation is achieved.
[0022] In a further second embodiment, the lens is formed from a
molding material, wherein the lens covers the transmitter and at
least the receiver. In this embodiment, the receiver may be
provided with a lens, as well. Configuring the lens from a molding
material is simple and inexpensive in production. In addition, the
lens for the transmitter as well as the lens for the receiver may
be produced in a simple manner in one working step.
[0023] In a further second embodiment, the lens for the transmitter
is held in a retainer. The retainer is fixed onto the transmitter
and/or the receiver and positions the lens at a predetermined
distance to the transmitter. The retainer surrounds and covers the
transmitter. In addition, the retainer holds the lens laterally so
that interference radiation generated by the lens is blocked by the
retainer from striking the reception surface of the receiver. By
means of this, the interference radiation for the receiver may be
reduced.
[0024] In a further second embodiment, the transmitter is arranged
on the receiver or on the reception surface of the receiver.
Thereby, a simple design of low height is realized.
[0025] In a further second embodiment, the receiver comprises a
reception surface arranged on an evaluation chip. The reception
surface comprises a smaller surface than the evaluation chip. This
provides a simple and compact design of the receiver.
[0026] In a further second embodiment, a covering is provided with
a passage area. The passage area is transparent for measuring
radiation and for reflected measuring radiation. The passage area
comprises or, respectively, defines the transmitter space and the
reception space.
[0027] The passage area is embodied as a continuous surface. By
means of the covering, a further reduction of the interference
radiation may be achieved by means of a compact design of the
arrangement.
[0028] In a further third embodiment, the partial surfaces have a
striped shape. This embodiment is particularly advantageous if the
transmitter is arranged laterally to the receiver. For example, two
or more stripe-shaped partial surfaces may be provided. The partial
surfaces may have same lengths and widths. In addition, the
stripe-shaped partial surfaces may have differing lengths and/or
differing widths, depending on the chosen embodiment. Instead of
stripe-shaped partial surfaces, square or circular partial surfaces
may be provided, as well. Due to the possibility of activating or
deactivating the partial surfaces, a surface shape of the active
partial surfaces of the reception surface adapted to the measuring
situation may be realized. By means of this, reception of
interference radiation may be reduced or, respectively,
minimized.
[0029] In a further third embodiment, the partial surfaces have a
ring-shape wherein the transmitter is arranged in the reception
space above the reception surface. For example, the transmitter is
arranged centrally above the reception surface. A region of the
reception space shadowed by the transmitter may be covered,
deactivated or free from a reception surface. Additionally, a first
partial surface may be arranged around the shadowed area of the
reception surface in a ring-shaped manner. The at least one further
partial surface is embodied in a ring shape around the first
partial surface or, respectively, the first partial surfaces.
Depending on the measuring situation, at least one of the
ring-shaped partial surfaces may be deactivated and thereby reduce
reception of the interference radiation.
[0030] The ring-shaped configuration of the partial surface may,
e.g., be realized in the shape of circular ring surfaces. In this
context, the innermost partial surface may be configured as a
circular surface, as well, depending on the chosen embodiment.
[0031] In a further embodiment, the ring-shaped partial surfaces
have the shape of closed striped rings comprising a plurality of
striped sections abutting on each other in a rectilinear manner.
One striped ring may have at least three striped sections, in
particular four striped sections. In this embodiment, an innermost
partial surface may comprise a triangle surface, a rectangular
surface or a polyangular surface.
[0032] In a variation of the third embodiment, the reception
surface is embodied as a segmented photodiode or in the shape of a
plurality of photodiodes. By means of the segmented photodiode or
by means of the plurality of photodiodes, the proposed partial
surfaces may be realized simply and inexpensively. In addition, the
partial surface of the reception surface may be evaluated
independently from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The above-described properties, features and advantages of
the present invention as well as the manner in which they are
achieved will become clearer in context with the following
description of embodiment examples which are described in more
detail in conjunction with the drawings, in which:
[0034] FIG. 1 shows a schematic top view of a first embodiment of a
measuring arrangement having a transmitter and a receiver;
[0035] FIG. 2 depicts a schematic cross-sectional view through the
first embodiment;
[0036] FIG. 3 depicts a schematic view of a receiver, wherein the
side contour of the reception surface has a partial circle
shape;
[0037] FIG. 4 shows a schematic view of a receiver having a
U-shaped reception surface;
[0038] FIG. 5 depicts a further embodiment of a receiver having a
plurality of reception surfaces arranged in U-shape;
[0039] FIG. 6 shows a schematic view of a cross section through a
second embodiment of a measuring arrangement with a transmitter and
a receiver, wherein the transmitter is arranged in the reception
space of the receiver;
[0040] FIG. 7 depicts a top view of a second measuring
arrangement;
[0041] FIG. 8 shows a cross-sectional view through a further
embodiment of the second measuring arrangement;
[0042] FIG. 9 shows a cross-sectional view through a further
embodiment of the second measuring arrangement;
[0043] FIG. 10 depicts a schematic view of a third measuring
arrangement;
[0044] FIG. 11 depicts a schematic top view of a first embodiment
of the receiver having segmented reception surfaces;
[0045] FIG. 12 shows a schematic top view of a further embodiment
of the receiver having stripe-shaped circumferential reception
surfaces; and
[0046] FIG. 13 depicts a schematic top view of a further embodiment
of the receiver with reception surfaces having circular ring
shapes.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0047] In a schematic view, FIG. 1 depicts a top view of a first
embodiment of a measuring arrangement 4 comprising a transmitter 1
and a receiver 2. A part of an upper side of the receiver 2 is
embodied as a reception surface 3. A covering 5 is arranged above
the measuring arrangement 4, wherein the covering 5 is transparent.
The covering 5 comprises a transparent passage area 6. The passage
area 6 is transparent for a measuring radiation of the transmitter
and for a measuring radiation received by the reception surface 3
and reflected at an object. The covering 5 may, for example, be
formed from a non-transparent material and the passage area 6 may
have the form of an aperture. Furthermore, the covering 5 may
entirely consist of a transparent material and the region of the
covering 5 may be covered by a non-transparent layer outside of the
passage area 6. The covering 5 may, e.g., be formed from sapphire
or glass. The covering 5 may have the shape of a plate. The
covering 5 may be arranged above the measuring arrangement 4 in
such a way that electromagnetic radiation of the transmitter 1 may
be radiated through the passage area 6 to an object to be measured.
The passage area 6 is arranged relative to the reception surface 3
in such a way that a measuring radiation reflected by the object to
be measured is radiated back to the reception surface 3 via the
passage area 6. It is a function of the covering 5 with the passage
area 6 to block interference radiation that is measuring radiation
not reflected by the object. The covering 5 thus provides that as
much reflected measuring radiation as possible strikes the
reception surface 3 and as little interference radiation as
possible strikes the reception surface 3.
[0048] The transmitter 1 is configured to transmit electromagnetic
radiation, in particular infrared radiation, visible light or
ultra-violet radiation. The transmitter 1 may, e.g., be configured
as a light-emitting diode or as a laser diode being a semiconductor
chip. The receiver 2 comprises an evaluation chip 7 wherein the
evaluation chip 7 comprises electric and/or electronic circuits for
evaluating the reflected measuring radiation received by the
reception surface 3. The reception surface 3 may, e.g., be embodied
as a photodiode. The transmitter 1 and the receiver 2 with the
reception surface 3 may be in a close side-by-side arrangement with
regard to each other. The reception surface 3, the passage area 6
and the transmitter 1 are embodied in such a way that the passage
area 6 is utilized in an ideal manner.
[0049] FIG. 2 shows a schematic lateral view of the arrangement of
FIG. 1. The transmitter 1 and the receiver 2 are arranged on a
carrier 8. The covering 5 is configured as a transparent plate on
the bottom side of which a non-transparent layer 9 is arranged. The
layer 9 comprises an aperture as a passage area 6. Above the
covering 5, an object 10 to be measured is schematically depicted.
In the shown embodiment, the measuring arrangement 4 comprises a
housing cap 11 that is non-transparent for electromagnetic
radiation, particularly for the measuring radiation. The housing
cap 11 is connected to the carrier 8 and protects the transmitter 1
and the receiver 2 against environmental damage. The housing cap 11
comprises a recess 12 that is formed above the transmitter 1 and
above the reception surface 3. The recess 12 may be sealed with a
transparent material. In addition, a housing wall 13 is formed
between the transmitter 1 and the receiver 2. The housing wall 13
extends from an upper side of the carrier 8 up to a height above
the transmitter 1 and the receiver 2. In addition, the housing wall
13 extends at least over a longitudinal side of the transmitter 1.
In this manner, direct irradiation of measuring radiation onto the
reception surface 3 without reflection at the object 10 is
avoided.
[0050] The transmitter 1 is configured to transmit measuring
radiation 14 in the direction of the object 10 to be measured
through the recess 12 and through the passage area 6. The object 10
reflects at least a part of the measuring radiation 14 as reflected
measuring radiation back through the passage area 6 and the recess
12 onto the reception surface 3 of the receiver 2. The evaluation
chip 7 is configured to detect reception of the reflected measuring
radiation 15 in the reception surface 3 and to evaluate it.
[0051] Depending on the chosen embodiment, the housing cap 11 may
be formed from a transparent material and be entirely arranged
above the measuring arrangement 4 with the transmitter 1 and the
receiver 2 in a closed form. In this embodiment, the transparent
area of the recess 12 is realized by the housing cap 11 having a
non-transparent layer. The non-transparent layer has a recess
corresponding to the shape of the recess 12.
[0052] The transmitter 1 transmits the measuring radiation 14 in a
transmission space 16. In the depicted embodiment, the transmission
space 16 is determined by the housing wall 13 and the recess 12. At
the same time, a reception space 17 is formed via which measuring
radiation 15 reflected from the object 10 is radiated back to the
reception surface 3. The reception space 17 is determined by the
housing wall 13 and the recess 12. The transmission space 16 as
well as the reception space 17 are formed in such a way that the
object 10 is arranged in the transmission space 16 or,
respectively, in the reception space 17.
[0053] Depending on the chosen embodiment, a first optics 18 may be
arranged above the transmitter 1 and/or a second optics 19 above
the receiver 2 in order to achieve an improved beam formation. The
first and second optics 18, 19 may, e.g., be embodied as individual
lenses and be arranged in or above the recess 12. Depending on the
chosen embodiment, the first and second optics 18, 19 may be
realized as a shared optics, in particular as a shared lens. The
optics 18, 19 may be formed from a molding material. In addition,
it is conceivable that instead of optics a cover layer without a
lens function is formed in the recess 12 or, respectively, on the
housing cap 11. The cover layer seals the recess 12 and protects
transmitter 1 and receiver 2 against environmental damage.
[0054] FIGS. 3 to 5 are schematic depictions of optimized planar
embodiments of the transmitter 1 and the receiver 2. In this
context, only the transparent passage area 6 and the planar
embodiment of transmitter 1 and the reception surface 3 are
schematically shown.
[0055] FIG. 3 shows a circle-shaped passage area 6 with a
transmitter 1. The transmitter 1 has a smaller surface than the
reception surface 3. The reception surface 3 is in this embodiment
formed as a partial circle surface. As a result, a side contour 20
of the reception surface 3 has an approximately similar or
identical shape as the limiting contour 21 of the passage area 6.
In the depicted embodiment, the reception surface 3 has a
half-circle shape. Depending on the chosen embodiment, the
reception surface 3 may also comprise a smaller part than a
half-circle surface or a larger part than the half-circle
surface.
[0056] Further utilization of the surface determined by the passage
area 6 and available for measuring is shown in FIG. 4. In this
embodiment, the reception surface 3 has a U-shape. The reception
surface 3 comprises two legs 22, 23 that are connected to each
other via a connecting surface 24. The transmitter 1 is arranged
between the legs 22, 23 of the reception surface 3. In this
embodiment, as well, the reception surface 3 has a partly
circle-shaped side contour 20. The side contour 20 thereby extends
over more than a half-circle surface and, e.g., up to almost a
three-quarter-circle shape. The transmitter 1 has a basic surface
that is configured as a square or as a rectangle. Depending on the
chosen embodiment, the transmitter 1 may also have a circular base
shape.
[0057] An advantage of the described arrangement is that as much
surface as possible of the reception space is covered by the
reception surface 3. The reception space is determined by the size
and shape of the passage area 6. Depending on the chosen
embodiment, in the embodiments of FIG. 3 and 4 the side contours 20
of the reception surface 3 may be formed independently from the
circle shape of the passage area 6. For example, in both
embodiments the reception surface 3 may laterally protrude over the
passage area 6 and thus over the reception space and the reception
surface 3 may be rectangular or have a square outer contour. Thus,
in these embodiments the reception surface may at least partly have
a rectilinear or partially jagged shape.
[0058] FIG. 5 shows a further embodiment for an inexpensive and
efficient covering of the reception space having a reception
surface 3. In this embodiment, the reception surface 3 has the
shape of three partial reception surfaces 31, 32, 33. The first and
third partial reception surface 31, 33 are rectangular and form a
first or, respectively a second leg 22, 23 of a U-shape. The second
partial reception surface 32 is rectangular, as well, and arranged
between two ends of the first and third partial reception surface
31, 33. The second partial reception surface 32 forms a connecting
surface 24 of the U-shape. Depending on the chosen embodiment, the
second partial reception surface 32 may be square. Between the
first and the third partial reception surface 31, 33, a transmitter
1 is arranged. By means of the depicted embodiment comprising a
plurality of partial reception surfaces 31, 32, 33, an inexpensive
and efficient covering of the reception space may be realized. For
example, the partial reception surfaces 31, 32, 33 may be three
photodiodes. In addition, depending on the chosen embodiment, one
single segmented photodiode may be used in order to depict the
first, second and third partial reception surface 31, 32, 33.
[0059] Due to an adjusted sensor geometry, the reception surface
may be used for receiving the reflected measuring radiation in an
improved manner. In particular, the measuring arrangement is
configured to transmit and receive infrared signals. Due to the
reception surface being larger relative to the available passage
are 6 or, respectively, the reception space 17 defined thereby, a
higher degree of sensitivity is achieved. Ideally, the surface of
the transmitter 1 and the reception surface 3 of the receiver 2
cover the entire reception space 17.
[0060] FIGS. 6 to 9 show embodiments of a second measuring
arrangement in which the transmitter 1 is arranged in the reception
space 17. FIG. 6 shows a measuring arrangement 4 having a receiver
2 arranged on a carrier 8. On an upper side 25 of the receiver 2, a
reception surface 3 is formed. In addition, a transmitter 1 is
arranged on or above the upper side 25 of the receiver 2. In the
depicted embodiment, the transmitter 1 is directly arranged on the
upper side 25 of the receiver 2, i.e., on the upper side of the
evaluation chip 7. The reception surface 3 is formed around the
transmitter 1 in a ring-shaped manner. Between the transmitter 1
and the reception surface 3, an inactive reception surface 34 is
formed around the transmitter 1 in a ring-shaped manner.
[0061] The inactive reception surface 34 is, e.g., realized by not
providing a reception surface 3, i.e., no photodiode. In a further
embodiment, the inactive reception surface 34 may be realized by a
non-transparent cover covering the reception surface 3 in the area
of the inactive reception surface 34. Furthermore, the inactive
reception surface 34 may be realized by a sensor cover 35 covering
the reception surface. The sensor cover is shown as a dotted line
in FIG. 6. In a further embodiment, the inactive reception surface
34 may be realized by the reception surface 3 being deactivated in
the area of the inactive reception surface 34 and not being used
for evaluating the received reflected measuring radiation. The
inactive reception surface 34 arranged in a ring-shape around the
transmitter 1 has the advantage that less interference radiation is
received by the reception surface 3. An area adjacent to the
transmitter 1 shows an increased interference radiation that is not
reflected measuring radiation.
[0062] Above the transmitter 1 and the receiver 2, a covering 5
having a non-transparent layer 9 is provided. The non-transparent
layer 9 comprises an aperture forming a passage area 6. The
covering 5 consists of a material transparent for the measuring
radiation and reflected measuring radiation. The non-transparent
layer 9 consists of a material non-transparent for the measuring
radiation and reflected measuring radiation. The covering 5 may,
e.g., consist of glass, sapphire or plastic. Above the covering 5,
the object 10 to be measured by means of the measuring radiation is
schematically shown. The measuring radiation 14 radiated by the
transmitter 1 may be reflected as an interference radiation 37,
e.g., at a boundary surface of a first optics 18. In addition, the
measuring radiation 14 may be reflected as an interference
radiation 37 at the covering 5. The interference radiation 37 is
thus reflected back to the transmitter 1 or, respectively, the
receiver 2 in a narrow angle with regard to the direction of
radiation of the measuring radiation 14. As a result, the
interference radiation 37 either directly strikes the transmitter 1
or the adjacent areas of the receiver 2. The adjacent areas are
formed as inactive reception surface 34 in order to reduce or,
respectively, to prevent reception of interference radiation at the
reception surface 3.
[0063] The inactive reception surface 34 is formed in such a way
that measuring radiation 15 which is reflected back from the object
10 in the direction of the reception surface 3 of the receiver 2
actually strikes an active reception surface 3 or, respectively,
the reception surface 3. Depending on the chosen embodiment, the
inactive reception surface 34 and the reception surface 3 or,
respectively, the entire receiver 2 may be covered with a
protective layer 36. The protective layer 36 may at the same time
have an optical guiding function for the reflected measuring
radiation 15. In addition, the first optics 18 and the protective
layer 36 or, respectively, the second optics 19 may be formed as a
one-piece optics, particularly from a mold material.
[0064] FIG. 7 shows a schematic top view of the arrangement of FIG.
6. In this context, the covering 5 is depicted transparently and
the shape of the passage area 6 is indicated by a dashed line. In
the depicted embodiment, the transmitter 1 has a rectangular base
surface. Likewise, the inactive reception surface 34 has a ring
shape comprising a rectangular outer contour and a rectangular
inner contour. The inactive reception surface 34 may have a
rectangular shape over which or on which the transmitter 1 is
arranged. Moreover, the reception surface 3 has a ring shape with a
rectangular outer contour and a rectangular inner contour.
Depending on the chosen embodiment, the reception surface 3 may
also be ring-shaped surface. Likewise, the inactive reception
surface 34 may have a ring-shaped surface. For example, the
inactive reception surface 34 may be embodied as a circular disc,
above or on which the transmitter 1 is arranged. Moreover, the
transmitter 1 may have a circle shape as its base shape.
[0065] By stacking transmitter and receiver on top of each other as
well as by preferably bundling the measuring radiation 14 by means
of a first optics 18, the measuring arrangement may be reduced with
regard to its planar expansion. A shadowed area of the transmitter
1 on the reception surface 3 may be reduced by correspondingly
forming the size and/or the shape of the inactive reception surface
34. In addition, the surface areas 38 of the reception area not
covered by the reception surface 3 may be used for arranging
further sensors.
[0066] In a schematic cross-section, FIG. 8 shows another example
for the second embodiment according to FIG. 6; however, in this
embodiment the first optics 18 is, e.g., directly arranged on the
transmitter 1 as a lens. Due to the geometric limitation of the
first optics 18 on the upper side of the transmitter 1, an
interference radiation 37 that may strike the reception surface 3
is reduced.
[0067] FIG. 9 shows another variant of the second embodiment of the
measuring arrangement of FIG. 6 in which the interference radiation
37 may further be reduced. For this purpose, a retainer 39 is
provided for the first optics 18. The retainer 39 is in this
embodiment formed as a housing that covers the transmitter 1 and
positions the first optics 18 in the direction of radiation of the
measuring radiation 14 above the transmitter 1. The retainer 39
surrounds the transmitter 1 and is arranged on the inactive
reception surface 34. The retainer 39 is positioned in the first
optics 18 that is, e.g., a lens at a predetermined distance in the
direction of radiation of the measuring radiation 14 above the
transmitter 1. As a result, no interference radiation of the first
optics 18 reaches the reception surface 3. Moreover, in this
embodiment the transmitter 1 is arranged on the inactive reception
surface 34, as well.
[0068] Depending on the chosen embodiment, the inactive reception
surface 34 may also be realized by not using a part of the
reception surface 34 for evaluating the measuring signal. For
example, the reception surface 3 may be a photodiode comprising
segmented areas. Said segmented areas may also be separate
photodiodes. As a result, an inner area of the reception surface 3
may be formed as a first segmented area that is an inactive
reception surface 34 and is not used for evaluating the reflected
measuring radiation 15.
[0069] The transmitter 1 may be configured as a highly bundled
light source, in particular as a laser diode such as VCSEL.
Furthermore, additional optics such as a lens in the housing cap or
a mold lens directly arranged on the carrier may achieve further
optimization or focusing of the measuring radiation. Strong
bundling of the measuring radiation of the transmitter is
advantageous in order to reduce an interference radiation. The
carrier 8 may comprise a multi-layer laminate, e.g., made of FR4.
In this context, the transmitter 1 may at first be charged to the
multi-layer laminate. Subsequently, the receiver 2 may be mounted
onto the carrier 8. Then, the transmitting and receiving unit may
be deposited on a reflector. For mechanical protection, a cap may
be applied to the substrate. The cap may at least comprise a lens
for the transmitter and/or a second lens for the receiver.
[0070] FIGS. 10 to 13 show embodiments of a third measuring
arrangement or, respectively, reception surfaces of a receiver of
the third measuring arrangement. FIG. 10 show a schematic lateral
view of a transmitter 1 arranged on a carrier 8. Beside the
transmitter 1, a receiver 2 is arranged on the carrier 8 at a
predetermined distance to the transmitter 1. The receiver 2
comprises a reception surface 3 on an upper side of the evaluation
chip 7. Above the measuring arrangement 4, a covering 5 is
arranged. The transmitter 1 transmits measuring radiation 14 in the
direction of an object 10 to be measured which is arranged above
the covering 5. The measuring radiation 14 may be reflected on the
bottom side and on the upper side of the covering 5 and guided in
the direction of the reception surface 3 as interference radiation
37. Thus, in a first area 41 of the reception surface 3,
interference radiation 37 is received. Reflected measuring
radiation 15 laterally strikes the first area 41 of the reception
surface 3.
[0071] FIG. 11 is a schematic top view of the reception surface 3
of the receiver 2 of FIG. 10. The reception surface 3 comprises
four strip-like segments 41, 42, 43, 44. The four segments 41, 42,
43, 44, e.g., form four reception areas of a photodiode. By means
of forming the photodiode 3 with segments, depending on the chosen
evaluation the four areas 41, 42, 43, 44 may be used independently
from one another by the evaluation chip 7 to evaluate the received
reflected measuring radiation 15. Thus, depending on the respective
measuring situation, at least one of the areas or several areas,
particularly all areas 41, 42, 43, 44, may not be taken into
account during detection of the reflected measuring radiation 15.
In this manner, an individual adjustment of the evaluation
situation of the segmented areas 41, 42, 43, 44 may be realized by
means of the evaluation chip 7. The four segmented areas 41, 42,
43, 44 may also be formed as four separate photodiodes.
[0072] FIG. 12 shows a schematic top view of a further embodiment
of a measuring arrangement 4 with a receiver 2 on which a
transmitter 1 is arranged. As a result, this arrangement of the
transmitter 1 and of the receiver 2 essentially corresponds to the
second measuring arrangement of FIGS. 6 to 9.
[0073] In this embodiment, the receiver 2 is carried out with an
evaluation chip 7 on the upper side of which a reception surface 3
is formed as a segmented photodiode. The photodiode comprises a
first central area 41. In the depicted embodiment, the first area
41 has a rectangular shape. The first area 41 is surrounded by a
second area 41 in a ring-shape. The second area 42 is surrounded by
a third area 43 in a ring-shape. The third area 43 is surrounded by
a fourth area 44 in a ring-shape. The second, third and fourth area
each have a rectangular inner contour and a rectangular outer
contour. Depending on the chosen embodiment, the ring-shaped areas
42, 43, 44 may have the same or different widths. Particularly, the
fourth and hence outer area 44 may have a larger width than the
third and/or the second area 43, 42.
[0074] Depending on the chosen embodiment, the first area 41 may
not be embodied as a reception surface and thus, only the second,
third and fourth area 42, 43, 44 may be embodied as segmented
photodiode areas. Depending on the respective measuring situation,
at least one of the areas 41, 42, 43, 44 may not be taken into
account during evaluation of the received reflected measuring
radiation 15.
[0075] FIG. 13 depicts an embodiment basically corresponding to the
design of the arrangement of the transmitter and receiver of FIG.
12. In this context, a receiver 2 having an evaluation chip 7 is
provided, on the upper side of which a reception surface 3 is
formed. In the center of the reception surface 3, a transmitter 1
is arranged. The transmitter 1 is arranged on a first circularly
shaped area 41. The first circularly shaped area 41 is surrounded
by a circular ring-shaped second area 41. The second ring-shaped
area 42 is surrounded by a third ring-shaped area 43. Depending on
the chosen embodiment, a fourth area 44 may surround the circular
ring shape of the third area 43 in a ring shape. The individual
areas 41, 42, 43, 44 may be formed as segmented areas of a
segmented photodiode. In this way, depending on the chosen
embodiment, at least one of the areas 41, 42, 43 may not be taken
into account for evaluation of the received reflected measuring
radiation 15. In addition, depending on the chosen embodiment, the
first area 41 may be formed as an inactive reception surface or,
respectively, it may not be formed as a reception surface 3. This
embodiment may be advantageous if too much interference radiation
37 is received in the first area 41 due to the existing measuring
arrangement.
[0076] The reception surface 3 may be formed as a photodiode with
segmented areas wherein the segmented areas 41, 42, 43, 44 may be
individually connected or disconnected for evaluating the reflected
measuring radiation. In case of a small air gap to the covering 5,
all segments 41, 42, 43, 44 may thus be used for evaluation. In
case of a larger air gap between the transmitter and the covering
5, individual segments may be excluded for evaluation. The larger
the air gap becomes, the more areas or segments of the photodiode
are switched off. The areas or segments may be embodied in such a
way that their structure is smaller in the critical area than in
the non-critical area. A critical area is characterized by a
probability for a higher interference radiation. As a result, an
adjustment to the measuring situation may be carried out in a
precise manner without losing too much sensitivity due to the
decrease in reception surface. The segments, i.e., the areas 41,
42, 43, 44 of the photodiode may be carried out as desired. For
example, the areas may be rectangular, ring-shaped or they may have
different shapes.
[0077] By switching off selected segmented areas 41, 42, 43, 44 of
the reception surface 3, a cross-talk may be faded out depending on
the assembling situation of the measuring arrangement. As a result,
the measuring arrangement may be operated in an optimized manner
for a specific assembling situation. The measuring arrangement 4 is
an optical sensor, wherein the sensor surface is geometrically
optimized in order to allow for as small an aperture in the housing
as possible.
[0078] The measuring arrangement is, e.g., suitable for detecting a
pulse of a person and/or for detecting a blood composition, in
particular an oxygen concentration. For this purpose, infrared
radiation is used as a measuring radiation. Furthermore, the
measuring arrangement may be used as a proximity sensor.
[0079] The present invention was depicted and described in detail
in connection with preferred embodiment examples. However, the
present invention is not limited to the disclosed examples. Rather,
a person skilled in the art may derive other variations without
exceeding the invention's protective scope.
* * * * *